The present invention relates generally to an oil separator for a compressor. More specifically, the present invention relates to an oil separator that separates oil from gaseous medium by impingement.
In a typical automotive air conditioning system, a mixture of oil and refrigerant enters the compressor through its suction port and is compressed through a reciprocating action of one or more pistons. The compressed, high-pressure refrigerant-oil mixture exits from the compressor through discharge ports to make its cyclic journey around the air conditioning system.
The aforementioned system is known as “oil in circulation.” Although the oil is carried around the entire air conditioning system and lubricates the compressor upon entering the compressor as a mixture within the refrigerant, the compressor is the only component in the system that requires constant lubrication. Thus, as the oil refrigerant mixture circulates through the system, the oil coats on the tubes and fins of the condenser and evaporator. The presence of oil on the tubes and fins of the heat exchanger compromises the heat transfer efficiency of the system. Hence, the customer feels warmer air being discharged from the vehicle's registers. The oil that coats the heat exchanger is ultimately wasted because it does not cycle back to the compressor. With the advent of micro-channel heat exchangers, the likelihood that the oil will clog up the narrow tubes is more probable.
Moreover, in a clutchless compressor, the compressor never entirely shuts off. That is, instead of cycling off to prevent refrigerant flow, the compressor reduces its displacement and minimizes the flow of refrigerant. This type of compressor also features a check value which prevents any undesired flow of refrigerant from entering the air conditioning system. Because the compressor has not cycled off, but has merely reduced its displacement volume, the internal components are still in motion and are therefore generating friction and heat. Hence, these components still require constant lubrication. This lubrication, however, is not available under such conditions with the conventional oil in circulation technique. Thus, the compressor must rely on whatever oil has been retained within the compressor to lubricate the components.
From the above, it is seen that there exists a need for an improved oil separator for air conditioning compressors.